I. Field of the Invention
The present invention relates to agents for complexing sodium under biological conditions. More particularly, the present invention relates to benzyl beta-d-glucopyranosiduronic acid and the salts and esters thereof as agents for complexing sodium. The present invention also relates to a method of synthesizing these agents and to their uses in biological systems.
II. Description of the Relevant Art
Living organisms require large quantities of sodium to maintain normal body function. Sodium chloride satisfies an essential mineral need that must be constantly replenished. For example, an adult human must consume about three grams of NaCl daily. Even more of this mineral must be consumed if vigorous activity is undertaken.
Human blood plasma has a very high concentration of sodium which, for the most part, is contained within extracellular fluids ( 142.0 m Eq/l as compared with 10.0 m Eq/l in intracellular fluids) . High concentrations of positively charged ions, such as sodium (Na.sup.+) , potassium (K.sup.+), and calcium (Ca.sup.+2) are particularly important in, for example, the conduction of nerve impulses, the contraction of muscle fibers, and for maintaining the normal permeability of cell membranes.
When nerve cells are at rest, the concentration of sodium ions on the outside of the cell membrane is greater than on the inside. The opposite is true for potassium ions. Large numbers of negatively charged ions are provided within the cytoplasm. Because cell membranes are slightly permeable to sodium ions and are highly permeable to potassium ions , the latter tend to diffuse freely through the membrane to the outside, while the sodium ions tend to diffuse slowly into the cell. Because the cell membrane expends energy during active transport to carry these ions in opposite directions, equilibrium is not reached, and as a result, sodium ions are actively transported outward through the membrane, while potassium ions are transported inward. The net effect of this transaction is for more positively charged ions to leave the cell than to enter it, and the outside of the membrane becomes positively charged with respect to the negative charge on the outside.
Sodium ions account for nearly 90% of the positively charged ions in extracellular fluid. The primary regulation mechanism that regulates the numbers of sodium ions involves the kidneys and the hormone aldosterone. This hormone is secreted by the adrenal cortex. This system does not, however, always operate in proper balance.
As is so often the case in the event of hypertension, increased levels of angiotensin, a powerful vasoconstrictor, results in increases in the peripheral resistance in the arterial system. This causes the arterial pressure to rise.
Angiotensin also causes aldosterone to be released from the adrenal cortex. Because the hormone promotes the retention of sodium ions and water by the kidneys, the resulting increase in blood volume causes an additional increase in blood pressure.
Other problems are attendant excess sodium ions in relation to the human body. For example, hair loss is thought to be related to the presence of an overabundance of sodium ions on the skin.
Accordingly, a method and composition is wanting that would safely reduce the number of excess sodium ions in the body while operating within the pH range of living systems . This is true because , while it is known that complexing agents and chelating agents are a valuable group of compounds (for example, versenes) , complexing agents for sodium ion are rare. Such rarities include, for example, crown ethers. However, while it is true that complexing agents for sodium ion are rare, complexing agents for sodium ion that function under physiological conditions are even more rare.